They can take a while to settle down to flowering once they've been moved - as in years. (I've been waiting three years now, for Tinkerbell, but she'd had an awful life before :-( )

Personally, I wouldn't put any Agapanthus in the dark. What I would do is keep it on the dry side over late autumn and winter, in good light and temperatures above freezing, then start to water again when growth begins - and keep it steady over summer. Bring your plants out into gentle daylight now and let them start toughening up.

Unless your summer sun is brutal - plenty of light is usually preferred to get good flowering. And excellent drainage to go with the reliable water.

They seem to be happy in unglazed terra cotta that's as deep as it's wide. Make sure it has sloping sides without any curled over rim because the Aggies have vigorous root systems and will need decanting for refreshing the soil. Pot feet are needed.

Organic liquid fertiliser such as worm casts at the recommended rate could also be helpful.

Hope that helps to get you a 'blue summer'!

Thanks for all the tips. clue me in. What is decanting? They are so crowded but I guess that is what they like. The roots are growing out of the bottom of one!

Agapanthus tolerate some crowding, but it is not their preferance. They divide easily. They are a fleshy rooted perennial not a bulb or a tuber and vertivert's advice is excellent. Give them as much sun as they can stand for the most blooms. Al